Improvement of helicopter performance using self - supplying air jet vortex generators

• Autorzy: Krzysiak A.
• Języki publikacji: EN

Abstrakty

EN

The work presents the results of experimental wind tunnel tests of using self-supplying air jet vortex generators to delay dynamic stall on helicopter blade due to attain high angles of attack. The dynamic stall which may appear on retreating helicopter blade is considered as the most severe type of stall, characterized by a strong vortex that forms on the blade’s upper surface. Its appearance is a significant limitation of helicopter performance. To improve helicopter aerodynamic characteristics the using of self-supplying air jet vortex generators was proposed. In comparison with the conventional air-jet vortex generators, which are supplied with the air from an external compressor, the self-supplying generators receive air from the overpressure region situated in the nose part of the blade lower surface at the higher angles of attack. The paper presents a comparison of the effectiveness of both types of generators based on tests performed in low speed wind tunnel T-1 in the Institute of Aviation (IoA) in the range of Mach numbers M =0.05-0.1. The experimental tests modeling periodic changes of flow around helicopter blade airfoil equipped with proposed self-supplying air jet vortex generators were performed in tri-sonic wind tunnel N-3 (with 0.6 x 0.6 m test section) in the IoA for Mach numbers M = 0.2 and 0.3. The NACA 0012 airfoil model of 0.18 m chord length used in wind tunnel test was oscillating in pitch ( alfa = ±50 with frequency 5 Hz) about an axis located at 35% chord length from the airfoil leading edge.

Słowa kluczowe

EN

air vehicle; helicopter; applied aerodynamics; vortex generation

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2013
• Tom: Vol. 20, No. 2
• Strony: 229--236
• Opis fizyczny: Bibliogr. 9 poz., rys.

Twórcy

autor

Krzysiak A.

• Institute of Aviation Krakowska Av. 110/114, Poland, 02-256 Warsaw tel.: [phone] ext. 363, fax [phone]

Bibliografia

• [1] Post, M. L., Corke, T. C., Separation Control Using Plasma Actuators: Dynamic Stall Vortex Control on Oscillating Airfoil, AIAA Journal, Vol. 44, No. 12, pp. 3125-3135, 2006.
• [2] Coton, F., et al., Control of Rotorcraft Retreating Blade Stall Using Air-Jet Vortex Generators, Journal of Aircraft, Vol. 43, No. 4, Jul.-Aug., pp. 1169-1176, 2006.
• [3] Wallis, R. A., A Preliminary Note on a Modified Type of Air Jet for Boundary Layer Control, Report ARC CP 513, 1960.
• [4] Wallis, R. A., Stuart, C. M., On the Control of Shock-Induced Boundary Layer Separation with Discrete Air Jets,”Report ARC CP 595, 1962.
• [5] Pearcey, H. H., Stuart, C., Methods of Boundary-Layer Control for Postponing and Alleviating Buffeting and Other Effects of Shock-Induced Separation, SMF Paper No. FF-22., Institute of the Aeronautical Sciences, New York 1959.
• [6] Pearcey, H. H., Shock Induced Separation and Its Prevention by Design and Boundary Layer Control, Boundary Layer and Flow Control, edited by Lachmann, G. V., pp. 1312-1314, Pergamon, Oxford 1961.
• [7] Krzysiak, A., Control of Flow Using Self-Supplying Air Jet Vortex Generators, AIAA Journal, Vol. 46, No. 9, Sept. 2008.
• [8] Mc Croskey, W. J., Carr, L. W., McAlister, K. W., Dynamic Stall Experiments on Oscillating Airfoils, AIAA Journal, Vol. 14, No. 1, pp. 57-63, January 1976.
• [9] Carr, L. W., Progress in Analysis and Prediction of Dynamic Stall, Journal of Aircraft, Vol. 25, No. 1, pp. 6-17, 1988.